# 货架中出现的异常
class DuplicateSid(Exception):
    """
    货架号重复

    """

    def __init__(self, value='货架号重复!'):
        self.value = value

    def __str__(self):
        return repr(self.value)


class ErrorSid(Exception):
    """
    货架号长度错误，应该为4位

    """

    def __init__(self, value='货架号长度错误，应该为4位!'):
        self.value = value

    def __str__(self):
        return repr(self.value)


class NotFindSid(Exception):
    """
    货架号找不到

    """

    def __init__(self, value='货架号找不到!'):
        self.value = value

    def __str__(self):
        return repr(self.value)
